Spray Foam need repaired??

[Aggiestro]

Hi all,

I recently had to repair a roof transition section on my metal building/shop. To remove/replace the transition the 1.5” closed cell spray foam on the interior was cracked about 10 feet long as shown in the picture. The crack now has a very small gap now that the roof is back together. Question I have is do I need to repair this and if so what would be the best way? What problems might I have if I don’t? This is a non conditioned (currently) shop in Mid west Arkansas area. Hoping some spray foam experts can chime in. Thanks!!!

 

[Hobby_Man22]

This was a question I've always wondered that's never been answered. Can you just spray more over existing foam?

 

[930dreamer]

If the foam wasn't applied at the agreed thickness, wouldn't they just spray over it to build it up? Not sure this applies to a crack? I'd get some dyi foam and fill it in.

 

[jpaw]

I'd fill it with more foam or at the very least caulk it with stretchable caulk. You don't want moisture getting in there causing separation.

 

[dcg9381]

Hi all,

I recently had to repair a roof transition section on my metal building/shop. To remove/replace the transition the 1.5” closed cell spray foam on the interior was cracked about 10 feet long as shown in the picture. The crack now has a very small gap now that the roof is back together. Question I have is do I need to repair this and if so what would be the best way? What problems might I have if I don’t? This is a non conditioned (currently) shop in Mid west Arkansas area. Hoping some spray foam experts can chime in. Thanks!!!

That foam spray install looks great... Very little variation. That's one of the best installs I've seen.

I would not "repair" that. It's just a minor crack.

If you WANT to repair it, I would "cut" it out (create a "V" just like you would to weld metal) and then get one of the non-consumer spray cans of closed cell with an actual spray tip.

You can see a repair I did with a much larger crack (the attachment surface of the spray foam failed, causing the crack):

Roof insulation fail (closed cell foam)

Inspired by reading another "insulation" thread, I wanted to share a word of warning on one design using spray foam. I am (and have been) for the last decade a spray foam fan-boy, as the resulting heating/cooling costs on the structures (3 total so far) that I've done with spray foam have been...

www.garagejournal.com

But the repair will be pretty obvious.

 

[rlitman]

That foam spray install looks great... Very little variation. That's one of the best installs I've seen.

I would not "repair" that. It's just a minor crack.

If you WANT to repair it, I would "cut" it out (create a "V" just like you would to weld metal) and then get one of the non-consumer spray cans of closed cell with an actual spray tip.

You can see a repair I did with a much larger crack (the attachment surface of the spray foam failed, causing the crack):

Roof insulation fail (closed cell foam)

Inspired by reading another "insulation" thread, I wanted to share a word of warning on one design using spray foam. I am (and have been) for the last decade a spray foam fan-boy, as the resulting heating/cooling costs on the structures (3 total so far) that I've done with spray foam have been...

www.garagejournal.com

But the repair will be pretty obvious.

Great Stuff "consumer" foam isn't any different than the "pro" foam. It's just the needle tips you can put on the pro gun. If you don't have a pro gun, simply open the crack wide enough to fit the consumer grade can's straw in. Whatever you do, DO NOT put a pro needle tip on that straw. Resist that urge at all costs, because if you do something that stupid (ask me how I know...), the back-pressure from the tip will cause the straw to pop off the valve fitting, causing all of the pressurized foam in the straw to blow back towards you and expand into a garter snake of evil stickiness.

But really, I'd just caulk it with a urethane caulk. Lexel will stick to urethane, and dries clear.

 

[dcg9381]

Great Stuff "consumer" foam isn't any different than the "pro" foam.

I tried fixing that crack (above link) with consumer grade great stuff.. It's sorta made to "pour" out versus the "spray" velocity of the other stuff. The pro stuff came with a can of tip cleaner too. If they are the same foam, I get it.

I've got no problem with filling that with urethane caulk.. Might cover up the optics of the crack.

 

[rlitman]

... consumer grade great stuff.. It's sorta made to "pour" out versus the "spray" velocity of the other stuff...

I've seen a lot of variation from can to can (and brand to brand). I think it also depends a lot on how well it's shaken, how far you're down in the can, what temperature it is, and how old the can is. For the record, when I refinished my basement, I used an elongated gun with needle tips and cases of foam cans to seal up every inch of seam in the tongue and groove subfloor above. Every night for a month I'd replace the old clogged tip, slap a new can on the gun and go up and back until it was empty and my arm was sore. The conical needle tips really can chase small cracks that the straw can't compete with, but that's such overkill for such a small job.

 

[dcg9381]

I've seen a lot of variation from can to can (and brand to brand).

The consumer stuff also has a lot of variation in foam type. You've got expanding and non-expanding. There is "high temperature" a high temp version too. If this will work with the right tip, I'm in... But I didn't have much luck with this stuff trying to re-spray a roof deck at a 45 degree "snow load" pitch...

I've always sprayed at temps above 70, so can't speak to that.. But I'm sure there is a point where temp matters.

 

[Grimm_the_Grey]

The consumer stuff also has a lot of variation in foam type. You've got expanding and non-expanding. There is "high temperature" a high temp version too. If this will work with the right tip, I'm in... But I didn't have much luck with this stuff trying to re-spray a roof deck at a 45 degree "snow load" pitch...

I've always sprayed at temps above 70, so can't speak to that.. But I'm sure there is a point where temp matters.

Next time. Try lightly misting the surface before applying the foam. It speeds curing and, in my opinion, makes it stick a little better.
Also great stuff now sells large cans with high-velocity conical and fan spray tips. The come in packs of two at my local bLowes, check yours.

If you're feeling adventurous, puncturing the can with 3/32 screwdriver creates a very nice, high-pressure stream, but you gotta be quick

 

[karoc]

 

[Grimm_the_Grey]

These are great, they do not last very long at all, so make sure everything's in place and ready to go, to avoid wasting any. They come with 4 spray tips, two fan-spray and two conical spray

 

[Kangaroo1956]

Hi all,

I recently had to repair a roof transition section on my metal building/shop. To remove/replace the transition the 1.5” closed cell spray foam on the interior was cracked about 10 feet long as shown in the picture. The crack now has a very small gap now that the roof is back together. Question I have is do I need to repair this and if so what would be the best way? What problems might I have if I don’t? This is a non conditioned (currently) shop in Mid west Arkansas area. Hoping some spray foam experts can chime in. Thanks!!!

I would go down the ridge and put a 3" screw every 12", leaving 1.5" sticking out to spray High-density foam over. Live life and be happy.

 

[imma_stocker]

Great Stuff 1" gap from the big box store is about the same material as commercial closed cell. Getting it to stick before falling or drooping might get messy with your application.